Journal
AMERICAN HEART JOURNAL
Volume 152, Issue 4, Pages -Publisher
MOSBY, INC
DOI: 10.1016/j.ahj.2006.07.007
Keywords
-
Categories
Ask authors/readers for more resources
Background beta-Blockers are effective for the treatment of heart failure, but their mechanism of action is unresolved. Heart rate reduction may be a central mechanism or a troublesome side effect. Methods A randomized, double-blind, parallel group study comparing chronic higher-rate (80 pulses per minute) with lower-rate (60 pulses per minute) pacing in pacemaker-dependent patients with symptomatic left ventricular (LV) systolic dysfunction, receiving beta-blockers. Gated radionuclide ventriculography (RNVG) was performed at baseline and after at least 9 months. The primary outcome was change in LV volumes, as a marker of beneficial reverse remodeling, from baseline to follow-up. Results Forty-nine patients were randomized. Mean age was 74 +/- 6 years and with LV ejection fraction of 26% +/- 9% at baseline. During 1 A 13 months of follow-up, 21 patients (43%) died and 25 (51%) completed the study protocol: 12 in the higher-rate and 13 in the lower-rate group. Mean LV end-diastolic (higher rate +20 +/- 104 mL vs lower rate -65 +/- 92 mL, P = .03) and systolic (higher rate +29 +/- 83 mL vs lower rate -60 +/- 74 mL, P = .006) volumes increased with higher-rate versus lower-rate pacing, whereas LV ejection fraction declined (higher rate -4.2% +/- 4.4% vs lower rate +2.2% +/- 5.4%, P = .002). Conclusion Reversal of p-blocker-induced bradycardia has deleterious effects on ventricular function, suggesting heart rate reduction is an important mediator of their effects. The prognosis of patients with pacemakers and heart failure is poor.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available